Fuse for projectiles.



T. B. DOE.

FUSE FOR PROJECTILES.

APPLICATION FILED MAY 4. 1918.

1,299,308. Patented Apr. 1,1919.

J/% i 2 SHEETS-SHEET I.

T. B. DOE.

FUSE FOB PR OJEQTILES. APPLICATION FILED MAY4. I9l8.

1,299,308. Patented Apr. 1,1919.

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1 TED STATES PATENT orrrcn.

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Specification of Letters Patent. v

Patented Apr. 1, 1919.

Application filed May 4, 1918. Serial No. 232,459.

hereof.

The object of this invention is to produce an improved fuse by which an explosive projectile can be detonated at a predetermined distance from the gun from which it is dis-' tion is established until the projectile reaches the limit of its flight, and that the velocity of flight and therefore the air pressure at its forward end diminish steadily from the time when the projectile leaves the gun. In the development of the present invention recognition of the relation of these two forces has been had and the operation of the fuse is made dependent upon the establishment of a determined relation, which will take place when the projectile has reached a given point in its flight, one of the forces being capable of regulation, so that the time or distance when the prescribed relation is established shall be capable of being regulated. In accordance with the invention a detent by which the hammer is restrained from effective movement is itself subject to movement in one direction by centrifugal action, to release the hammer, and is held against such movement by the air pressure until the air pressure, after flight of the projectile through a predetermined distance, has been reduced to a degree such as to permit the movement of the'detent by centrifugal force. The invention will be more fully explained hereinafter with reference -to the accompanying drlfilvlilngs in which it is illustrated, and in w jectile head or fuse which embodies the invention.

(Fig. 2 is a view of the same in axial section, indicated by the broken line 2-2 of Fig. 4, looking in the direction of the arrows, and on a larger scale than that of Fig. 1.

detent b and is thereby held in its seat Figure 1 is a view in elevation of the pro Fig. 3 is a view in transverse section on the plane indicated by the broken line 3-3 of Fig. 4., looking in the direction of the arrows.

Fig. 4 is a view partly in elevation and partly in section on an axial plane indicated by the broken line 4 --4 of Fig. 2,1ooking in the direction of the arrows, the plane of section being at right angles to that of Fig. 2.

The conical body a of the head or fuse, shown at a as screw-threaded in order that it may be secured in the'forward end of the shell, is formed at I) with a transverse chamber, preferably open at both ends, and adapted to receive the freely movable detent bf which fits .in the chamber 6 as a plunger. The head has in its forward end an axial opening a which communicates, through a channel'a with the chamber 6 near one end thereof. Mounted on the head a, so as to be rotarily adjustable, is a cap or skirt 0 which is adapted to cover more or less one end of the chamber 6, for the purpose of controlling and regulating the escape of air from that portion of the chamber behind the detent 6 into which air is forced from the channels a a in the flight of the projectile.

In the head, back of the chamber 6, is.

formed another transverse chamber at which is preferably disposed at right angles to the chamber 6 and is adapted to receive the hammer e which, when released, is driven forward by a spring'e'. One end of the chamber (1 is closed by a plugd, which forms an abutment for the spring 0. The other end of the chamber is closed by a plug (1 which carries the cap or primer d and communicates, through a suitable flash passage a, with the base charge a The hammer is provided with a channel e for the purpose of equalizing the air pressure on both sides of the hammer and is also provided with a conical recess e? to receive a ball-check f which is placed in a chamber f communicating with the chamber 15. The ball-check f is normally overlaid by' the in the hammer so as to prevent the movement of the hammer under the' influence of the spring e. When the detent is displaced by centrifugal action, as hereinafter explained, the'ball-check f is then free to be moved forward by the movement of the hammer e under the influence. of its spring and the hammer e is therefore released and detonates the cap d.

A safety lock 9 is also provided for the hammer, being operated to free the hammer by its own inertia when the gun is fired and the projectile begins its flight. This safety lock is provided with a projection g to enter a corresponding recess (2 in the hammer e and is seated in a chamber 9* formed to receive it in the body a. It is held in looking position by a split spring ring 9 which is received partly in a circumferential recess-g in the wall of the lock and partly in an internal recess 9 formed in a two-part sleeve 9. When the gun is fired the inertia of the lock 9 produces a relative movement of the lock and the head which disengages the lock from the hammer e. The spring ring 9 yields to permit such movement of the lock and when the lock is at its complete relative movement to the .rear the spring ring 9 resumes its original shape and prevents relative movement of the lock in a forward direction.

The cap or skirt 0 may be retained in place by a sleeve nut 71. which is threaded on the forward end of the head or conical body a. A wedge ring h, carried by the nut h, is interposed between the cap and the skirt and the head or body a and by its inertia, when the gun is fired, is driven bodily between the cap or skirt and the body so as to lock the cap or skirt in place against possible movement thereafter.

Since the air pressure begins to act upon the detent b somewhat more slowly than does the centrifugal force, it is desirable to provide means to prevent movement of the detent before the air pressure shall have been established. For this purpose the body a is formed with a chamber k in which is placed a locking body is, pressed normally into engagement with the detent b by a spring k which abuts against a plug h this locking body 70 being disengaged from the.

detent b by centrifugal action.

a In the use of the improved fuse, the parts all being in the positions shown in the drawings, when the gun is fired the safety lock g is immediately withdrawn from its engagement with the hammer e and soon thereafter through the action of the centrifugal force developed by the rotation of the projectile, the locking body In is withdrawn from engagement with the detent b, leaving it subject to the action of centrifugal force developed by the rotation of the projectile and to the air pressure developed by the flight of the projectile. The detent b, as will be observed, is somewhat unbalanced so that the tendency of the centrifugal force is to move the detent toward the left hand in Fig. 4 and thereby set free the hammer 6. Such movement of the detent I), however,

is resisted by the air pressure exertedthrough the channels a a against the rear face of the detent. In order that the detent b may not be moved by centrifugal force before the air pressure is established, it is held from movement briefly, but long enough to permit the air pressure to be established, by the locking body is, which must be moved by centrifugal force before the detent can be moved. The mass of the detent and the cross-sectional area of the passages a a and of the chamber 6 are calculated so that the force of the air pressure which holds the detent against movement shall exceed the centrifugal force which tends to move it in the opposite direction, until the flight of the projectile has slowed down sufliciently to make the' effect of the air pressure less than the effect of centrifugal force. When this takes place the detent will be moved by centrifugal force so as to release the hammer. -The fuse can be regulated so as to determine the point at which it shall operate, by regulating the air pressure behind the detent b. This may be accomplished by rotating the cap or skirt 0 which is cut off on a plane oblique to the axis, so that the left hand end of the chamber Z) may be more or less completely covered'to permit a more restricted or freer escape of air from the chamber. A scale may be formed on the nut h with'a pointer on the cap.or skirt '0, as shown in Fig. 1, to permit the extent of movement of the cap to be observed.

It will be understood that various modifications in details of construction can be made to suit the requirements of use or the convenience or preference of the manufacturer and that the invention, except as pointed out in the accompanying claims, is not limited to the precise construction shown and described herein.

I claim as my invention:

1. In a fuse, the combination of a hammer and a detent therefor subject to the action of centrifugal force in one direction, the fuse being formed with an air channel opening from the forward end whereby the detent is subject in the other direction to the action of air pressure-due to the flight ofthe projectile.

2. In a fuse, the combination of a hammer, a spring to move the hammer and a detent for the hammer subject-t0 the action of centrifugal force in one direction, the fuse being formed with an air channel opening from the forward end whereby the detent is subject in the other direction to the action-of air pressure due to .the flight of the projectile.

3. In a fuse, the combination of a body having a chamber for a hammer and a transto the action of air pressure to move it in r the opposite direction.

4;. In -a fuse, the combination of a body having a chamber for a hammer and a transverse chamber for a detent, an air channel opening from the forward end of the fuse 7/ and to the action of "air pressure to move'it in the opposite direction, and means toregulatethe escape of air from the transverse chamber behind the detent.

5. In a fuse, the combination of a body having a transverse chamber for a hammer,

a transverse chamber for a detent and an air passage from the forward end of the body to the second named chamber, a hammer mounted movably in the chamber therefor and a plunger detent mounted movably in the chamber therefor and subject to the action of centrifugal force to move it in one direction and to the action of air pressure tfo hold it against movement by centrifugal orce.

6. In a fuse, the combination of a body having a transverse chamber for a hammer, a second transverse chamber for a detent, a

third chamber between the first two, and an air channel opening from the forward endof the fuse to the second named transverse chamber, a hammer mounted in .the first named chamber and having a recess in one sidethereof, a ball-check placed in the third chamber to cooperate with the'hammer and a plunger detent mounted movably in the second named chamber, said detent normally retaining the ball-check in its seat to hold the hammer from movement and held normally in locking Position by air pressure during the flight of the shell andmoved by centrifugal action against the diminishing air pressure to release the hammer.

7. In a fuse, the combination of a hammer, a safety lock normally engagin the hammer to prevent movement thereof and disengaged therefrom by inertia when the gun is fired, a detent to prevent movement of'the hammer and subject in one direction to the action of centrifugal force and in the opposite direction to the action of the air pressure, anda centrifugally operated locking body engaging the detent to prevent movement thereof before the air pressure is established.

This specification signed this first day of May, 1918.

' THOMAS B. DOE. 

